fix(gateway): detect coordinator staging before discharge ownership checks

A coordinator whose discharge end entity was not (yet) owned by the
gateway was refused with an ownership error instead of keeping its
staged separate-endpoint sequence. Identify coordinators first, as that
decision only needs the entity names and discovery record.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018BaJjLpuMEtQYfvmTRcFJf

Author: mgazza

apps/predbat/inverter.py

@@ -2944,13 +2944,13 @@ def write_and_poll_gateway_discharge_window(self, new_start, new_end):
         gateway = components.get_component("gateway") if components else None
         names = ("discharge_start_time", "discharge_end_time")
         target = (new_start, new_end)
+        if gateway is not None and gateway.discharge_window_uses_staging(*entities):
+            return None  # Coordinator slot staging must precede its enable write.
         if owners != ["gateway", "gateway"] or gateway is None:
             self.base.record_status(f"Warn: Inverter {self.id} Hub discharge window has inconsistent entity ownership", had_errors=True)
             return False
         if not all(self.check_write_entity("write_and_poll_gateway_discharge_window", name, entity, value) for name, entity, value in zip(names, entities, target)):
             return False
-        if gateway.discharge_window_uses_staging(*entities):
-            return None  # Coordinator slot staging must precede its enable write.
 
         def read_pair():
             """Read both endpoint entities without substituting desired values."""

apps/predbat/tests/test_gateway_discharge_window.py

@@ -1,4 +1,5 @@
 """Joined engine discharge window, command serialization and ACK regressions."""
+
 # cspell:ignore excepthook
 
 import asyncio
@@ -209,6 +210,16 @@ def test_other_provider_and_coordinator_keep_individual_sequence(self):
             self.assertEqual([json.loads(command["schedule_json"]) for command in wire if command["command"] == "set_discharge_slot"], [{"start": 255}, {"end": 301}])
             self.assertEqual(wire[-1]["command"], "set_discharge_enable")
 
+    def test_coordinator_with_partial_ownership_keeps_staged_sequence(self):
+        """A coordinator is identified before ownership checks, so it is never refused by them."""
+        for kind in GATEWAY_COORDINATOR_TYPES:
+            inv, gw, base, wire, mode = self.fixture()
+            gw._discovery = {"CE123456789": {"type": kind}}
+            base.dashboard_index_app[base.END] = None
+            self.apply(inv)
+            self.assertFalse(any("inconsistent entity ownership" in error for error in base.errors), kind)
+            self.assertEqual([json.loads(command["schedule_json"]) for command in wire if command["command"] == "set_discharge_slot"], [{"start": 255}, {"end": 301}])
+
     def test_disable_and_midnight_zero_window_remain_valid(self):
         """A disable request never activates export and may program midnight endpoints."""
         inv, gw, base, wire, mode = self.fixture(enabled="on")